Re: [PATCH] drm/i915: Enabling RC6 immediately during init/resume

Chris Wilson
2015-08-21T12:41:30Z

On Sat, Aug 22, 2015 at 02:19:48AM +0530, Namrta Salonie wrote:
> Since RC6 enabling does not involve PCU communication overhead,
> it can be enabled immediately during the resume time.
> This will help save additional power & meet power requirements
> for active Idle KPI where power is evaluated over
> number of transitions of suspend/resume.
>
> Signed-off-by: Namrta Salonie <namrta.salonie@intel.com>
> Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>

You can pull out gen9 rc6 as well, and apply a similar transformation to
gen6-8. So instead of putting the if-chain in
intel_enable_gt_powersave(), add intel_enable_rc6() and start placing
the ready functions there.

Reviewing the comments we only need the rpm lock until after rc6
enabling and as you keep that wakelock, you are not getting the full
improvement you seek. If you keep refactoring the remaining two rc6
functions, you can then drop the wakelock.
-Chris

--
Chris Wilson, Intel Open Source Technology Centre